# $$,获取当前pid.
# $$,并没有新建进程,那是线程?
#
#
echo task for:
for ((Time=10;Time>0;Time--))
do
    echo  "sub task ${Time},pid: $$"
    sleep 1
done &

for ((Time2=10;Time2>0;Time2--))
do
    echo  "main task ${Time2},pid: $$"
    sleep 0.5
done


